In today's business and scientific world, color has become essential as a component of communication. Color facilitates the sharing of knowledge and ideas. Companies involved in the development of digital color print engines are continuously looking for ways to improve the total image quality of their products. One of the elements that affects image quality is the ability to consistently produce the same quality image output on a printer from one day to another, from one week to the next, month after month. Colors on a printer tend to drift over time due to ink/toner variations, temperature fluctuations, type of media used, environment, etc. There has been a long felt commercial need for efficiently maintaining print color predictability, particularly as electronic marketing has placed more importance on the accurate representation of merchandise in illustrative print or display media.
Documents, i.e., viewable representations in either electronic or print format and inclusive of text, postures, graphics or other illustrative forms of any kind, are generally created electronically with sections from various input devices such as, for example, scanners, cameras, computer graphics, etc., in the “creative” stage of the production workflow. The documents are designed by assembling their contents using various layout tools. They are then assembled into jobs and evaluated for acceptability including design color quality. They are then typically proofed either on a monitor or on a workgroup digital printer. Up to this point of the document life cycle, typically, a standard reference press color model is used to estimate the expected print appearance and is retained with the electronic document. In other cases, graphic design color models are retained in the electronic document. In either case, when the electronic document is delivered from the “creative” stage of the workflow to the prepress and production stage, the colors carried in the designed document have to be transformed to press colors; i.e., the primary colors of whatever image forming device is being employed. In an automated color management environment, the original color model information delivered with the design document (either a standard reference press color model or a graphic design color model) is used as the “source” definition for the transform, and the actual (not measured real-time) press color model is applied as the “destination” for the transform. In a manual color management environment, a default press color transformation is applied, followed by manual on-press controls used to adjust the print results. In either case, typically, if the job is to be split and produced through more than one print system (print engine to print engine consistency), then manual tuning of those print systems, using on-press controls such as, for example, Digital Front End TRCs (Tone Reproduction Curves), is used to improve the match before production is initiated. Typically, press proofs are required during this match tuning process.
When a job has already been produced, and a future reprint may be expected, then the electronic document is retained, either in original design form with the embedded or associated graphic design color models or standard reference press color models, or in production form with the embedded or associated actual (not measured real-time) press color model. If production reprint color match is required, then a hardcopy sample from the first production run is retained for reference during reprint. At the time of reprint, manual tuning of the print system(s), using on-press controls such as, for example, Digital Front End TRCs, is used to improve the match to the original sample before production is initiated. Typically, press proofs are required during this match tuning process.
As is known, current production print shop owners want faster turn-around time in their print jobs. This means time pressures are increasing, requiring more uptime for presses. Many printshops own multiple presses to improve turn-around time.
As increasing numbers of press systems within a print shop operate in parallel, there will be an enhanced need for distributed optimization of interconnected workflows to ensure output consistency with little or no interruption. Distributed optimization of interconnected workflows is required to ensure output consistency when a job is split and produced through multiple print systems (print engine to print engine consistency), and to ensure output consistency when a job is produced at a later time (temporal consistency).
As is known, present methods of producing documents do not measure and retain information regarding the actual production state of the press.
To reduce cost and improve productivity in the prepress, production, and reprint life cycle, real-time feedback from the press of its latest functional models, defining the real-time correspondence between color encoding value and resulting measured color, becomes useful. These models contain reproducible color information remotely obtained from the press, and can include accommodation for screening, media, and other print condition specifics. These real-time, accurate color models will help prepress operators, or (preferably) automated color conversion workflow components, to carry out prepress functions efficiently on the documents. Accurate knowledge of the press color capabilities can improve the production efficiency considerably.
A job ticket is a stored program describing the preparation of a document, which can be created and edited anywhere and executed on a production device anywhere to generate complete sets of finished documents. Job tickets are specifically designed to provide the defining attributes for each portion of a print production process. They have evolved into industry-wide standards such as, for example, the Job Description Format (“JDF”) for the publishing industry. Current JDF standards can contain either standard reference press color models such as, for example, SWOP, CMYK, DeviceN, Pantone Named Colors, etc., specific actual (not measured real-time) press color models, or graphic design color models such as, for example, Adobe RGB. However, current job ticket process information does not include the idea of a real-time adjustment or update of the actual press color model.
Thus, there is a need for the present development.